WO2021077451A1

WO2021077451A1 - Digital guide plate for mandible distraction osteogenesis and manufacturing method therefor

Info

Publication number: WO2021077451A1
Application number: PCT/CN2019/114116
Authority: WO
Inventors: 罗恩; 杜文; 许春炜; 刘瑶; 白沅艳; 纪焕中; 赵文丽; 何�泽
Original assignee: 四川大学
Priority date: 2019-10-23
Filing date: 2019-10-29
Publication date: 2021-04-29
Also published as: CN110623715A

Abstract

A digital guide plate for mandible distraction osteogenesis and a manufacturing method therefor. The digital guide plate comprises: a first locating part (1) which is provided at an upper source of a front end, extends forwards along an outer side face of the mandible of a patient, and crosses over an outer oblique line of a mandibular ramus to form a surrounding structure; a second locating part (2) which is provided at a lower source of the front end, extends downwards along the outer side face of the mandible of the patient, and extends from below to the inner side of the mandible to form a surrounding structure after getting close to a mental foramen of the mandible; a third locating part (3) provided at a rear end and extends towards the inner side of the mandibular ramus along an outer rear edge of the mandibular ramus to form a surrounding structure; locating holes (4) for guiding bone drilling and a titanium nail fixing distractor; and a guide separation line for guiding an osteotomy direction of the mandible. According to the guide plate, distraction osteogenesis can be accurately designed and guided, the final treatment effect is improved, and surgical operation and burden of the patient are reduced as much as possible.

Description

Digital guide plate for mandibular distraction osteogenesis and manufacturing method thereof

Technical field

The invention relates to the field of auxiliary medical devices, and more specifically to a digital guide plate for mandibular distraction osteogenesis and a manufacturing method thereof.

Background technique

Unilateral mandibular underdevelopment and secondary maxillofacial deformities caused by various factors are more common in the clinical work of oral and maxillofacial surgery, and the treatment is more difficult. Distraction osteogenesis, as a technique that can effectively increase the bone mass of the patient's mandible, is widely used in the treatment of severe unilateral mandibular underdevelopment and secondary maxillofacial deformities. Distraction osteogenesis refers to the application of mechanical traction to the osteotomy area through osteotomy and procedural procedures to mobilize and activate the body's own ability to resist injury and regeneration to repair bone defects or extend bones. Patients with unilateral mandibular underdevelopment are often accompanied by secondary asymmetry of the jaw. Distraction osteogenesis is often used as a means to increase bone mass in conjunction with second-stage orthognathic surgery and contouring. Therefore, distraction The effect of osteogenesis is very likely to affect the entire treatment plan and the final treatment effect. Distraction osteogenesis requires the use of a special jaw distractor. At present, there are many kinds of finished distractors used in clinical distraction osteogenesis. The commonly used distractors in oral and maxillofacial surgery are mostly built-in linear distractors. The direction of distraction osteogenesis depends on the direction in which the distractor is placed, and different directions of distraction osteogenesis will have a great impact on the final treatment effect. In the past, the simulation of distractor placement in distraction osteogenesis surgery was mostly performed on X-rays. In recent years, with the development of digital technology and 3D printing technology, some doctors have simulated the placement of the distractor in three dimensions on the computer, or The patient's jaw model is formed by 3D printing, and the operation is simulated on it. However, these methods can only provide doctors with reference, and ultimately the jaw distractor still needs doctors to actually place them during the operation based on their experience. At present, there is no public report on the digital guide plate and design method for unilateral mandibular distraction osteogenesis to treat unilateral mandibular underdevelopment and secondary mandibular asymmetric deformities. The existing unilateral mandibular distraction osteogenesis For bone, two operations are required, and the patient's physical and economic burden is heavy.

Summary of the invention

In order to solve the above technical problems, the present invention provides a digital guide plate for mandibular distraction osteogenesis and a manufacturing method thereof.

The present invention is realized through the following technical solutions:

A digital guide plate for mandibular distraction osteogenesis, including:

The upper source placed at the front end extends forward along the lateral surface of the patient's mandible and crosses the outer oblique line of the mandibular ascending branch to form a first positioning portion of the wrapping structure;

The sub-source placed at the front end extends downwards along the lateral surface of the patient's mandible and after approaching the mandibular foramen, it extends from the inner side of the mandible to form a second positioning part of the enveloping structure;

The third positioning part is placed at the rear end and extends along the outer and rear edge of the ascending mandibular branch to form a surrounding structure;

Used to guide bone drilling and titanium nails to fix the positioning holes of the distractor;

Guide separation line used to guide the direction of mandibular osteotomy.

A method for manufacturing a digital guide plate for mandibular distraction osteogenesis, including the following steps:

A. Obtain the physical model of the upper and lower dentition;

B. Determine the relative position of the upper and lower dentition physical model after the operation and mark it as the terminal occlusal relationship, and obtain the digital model Y of the patient's upper and lower dentition;

C. Establish a digital model A of the patient's cranio-maxillofacial bone tissue, and mark the position of the inferior alveolar nerve tube;

D. Match the digital model Y to the upper and lower dentition positions of the digital model A, and obtain the upper jaw and skull model B with accurate upper jaw dentition and the mandibular model C with accurate lower jaw dentition;

E. Simulate the osteotomy line of the mandible that needs to distract the osteogenesis side in the mandibular model C, and register the bone block containing the uninvolved mandible and mandibular dentition to the maxillary and skull model B according to the terminal occlusal relationship. Below, the mandibular model C and the upper jaw and skull model B are taken as a whole, with the contralateral condyle as the axis, according to the position of the bone block after the operation, to simulate the digital model D of the craniomaxillofacial surface after the operation;

F. In the cranio-maxillofacial digital model D, simulate the direction of the guide rod of the mandibular distraction osteogenesis distractor on the operating side;

G. Import the distractor model used in the operation and place the retractor according to the direction of the guide rod, and adjust the position of the distractor by translation to make it fit the mandible bone surface of the mandible model C to be distracted.

H. According to the shape of the bent distractor, the female mold of the distractor that closely fits the shape is designed;

I. According to the position of the three positioning parts of the affected mandible, the position of the nail hole and the position of the simulated osteotomy line, draw the outline of a guide plate on the outer bone surface of the mandible of the affected side, and generate the first positioning part and the second positioning part of the above guide plate. The positioning part and the third positioning part, the inner surface of the guide plate fits with the outer bone surface of the mandible;

J. Add positioning holes and guide the separation line on the guide plate according to the position of the distractor nail hole and the mandibular osteotomy line;

K. Print the designed guide plate.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The digital guide plate of the present invention can realize the accurate design and guidance of distraction osteogenesis, improve the final treatment effect, and reduce the burden on surgical operations and patients as much as possible.

2. The use of this guide can be used for the overall consideration of the plan design for the surgery that originally required two operations, which can avoid unnecessary treatments during the two operations to a certain extent, and may reduce part of the surgical procedures during the second-stage operation. Reduce the patient's physical and economic burden.

Description of the drawings

The drawings described here are used to provide a further understanding of the embodiments of the present invention, constitute a part of the application, and do not constitute a limitation to the embodiments of the present invention.

Figure 1 is a schematic diagram of the structure of the guide plate of the scheme.

Figure 2 is the external side view of the guide plate and the mandible.

Figure 3 is a bottom view of the guide plate and the mandible.

Figure 4 is a physical map of the outside of the guide plate.

Figure 5 is a physical view of the inner side of the guide plate.

Fig. 6 is a top structural view of the female mold.

Figure 7 is a schematic diagram of the cooperation between the female mold and the virtual bending stretcher.

Figure 8 is a schematic diagram of the structure of the mandible and the distractor during the operation.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present invention clearer and clearer, the present invention will be further described in detail below with reference to the embodiments and drawings. The exemplary embodiments and descriptions of the present invention are only used to explain the present invention, not As a limitation of the present invention.

Example 1

As shown in Figure 1, a digital guide plate for mandibular distraction osteogenesis includes a first positioning portion 1, a second positioning portion 2, a third positioning portion 3, a positioning hole 4, a guide separation line 5, and a first The positioning portion 1, the second positioning portion 2, and the third positioning portion 3 constitute the main structure of the guide plate. The first positioning part 1 is placed at the front end of the main structure and the upper source extends forward along the outer side of the patient's mandible and crosses the outer oblique line of the mandibular ascending ramus to form an enveloping structure; the second positioning part 2 is placed at the front end of the main structure and the lower source is along the outer side of the patient's mandible Extend face down and near the mandibular foramen, extend from the inner side of the mandible to form an enveloping structure; the third positioning part 3 is placed at the rear end of the main structure and extends along the outer and posterior edge of the ascending mandibular branch to form the inner side of the ascending mandibular branch In the wrapping structure, the three are connected together to form a single body. The positioning hole 4 is used to guide bone drilling and titanium nails to fix the distractor, and can be set on the first positioning part 1, the second positioning part 2, and the third positioning part 3 according to requirements; the guide separation line 5 is used to guide the mandible The direction of osteotomy corresponds to the position of the patient’s osteotomy line.

Specifically, the thickness of the main structure is 2 to 3 mm, that is, the thickness of the first positioning portion, the second positioning portion, and the third positioning portion is 2 to 3 mm. In order to improve the stability of the guide plate fixing, there are at least three positioning holes on each positioning part of the first positioning part, the second positioning part, and the third positioning part.

Example 2

Based on the above structure, this embodiment discloses a specific manufacturing method of the above guide plate.

A. Obtain a physical model of the patient's upper and lower dentition. The physical model can be made of plaster. The upper and lower dentition impressions of the patient are obtained with impression materials, and the plaster is used to infuse them.

B. Determine the relative position of the upper and lower dentition physical model after the operation and mark it as the terminal occlusal relationship. Use the model laser scanner to obtain the digital model Y of the patient’s upper and lower dentition, and convert the upper and lower dentition in STL format And the final occlusal relationship is preserved.

C. Establish a digital model A of the patient's cranio-maxillofacial bone tissue, and mark the position of the inferior alveolar nerve tube. The digital model A can be established by Mimics software from CT data taken when the patient is in the resting position before the operation. After the digital model A is reconstructed, the digital model A is backed up and saved in STL format.

D. Match the digital model Y to the upper and lower dentition positions of the digital model A through the alignment function of the Geomagic software, and perform registration to obtain the maxillary and skull model B containing the accurate maxillary dentition and the accurate mandibular dentition. The mandible model C, the upper jaw and skull model B, and the mandible model C are saved in STL format.

E. Simulate the cutting of the mandible in the Freeform software. C. The osteotomy line of the mandible that needs to be distracted on the osteogenesis side. During the simulation process, try to avoid hurting the inferior alveolar nerve bundle and include the uninvolved mandible. The bones of the bone and mandibular dentition are registered under the maxillary and skull model B according to the terminal occlusal relationship. The mandibular model C and the maxillary and skull model B are taken as a whole, with the contralateral condyle as the axis, according to aesthetics The standard design of the position of the bone block after the operation is to simulate the digital model D of the craniomaxillofacial area after the operation and save it in STL format;

F. Use Freeform software to simulate the direction of the guide rod of the mandibular distraction osteogenesis distractor on the surgical side in the cranio-maxillofacial digital model D. This direction is the side where the distraction osteogenesis is required, and the mandibular stump corresponds to both sides Point of the connection.

G. Import the distractor model used in the operation and place the retractor in the direction of the guide rod, and adjust the position of the distractor by translation to fit the mandible bone surface of the mandible model C to be distracted. The ratio of the distractor model to the distractor during the operation is 1:1. The placement of the distractor needs to be considered: ①Whether the mandibular ends on both sides have enough bone for titanium nail fixation (the mandibular titanium nails on each side should be three or more); ②The fixation position of the titanium nails should be avoided. Cut the alveolar nerve tube and tooth root; ③The distraction device is usually placed by submandibular extraoral approach, and the placement position of the simulated distraction device should be placed as low as possible; ④The simulated bone resection line can be designed according to the actual surgical needs. It is a straight line, it can also be a broken line or a zigzag shape, and the placement of the distractor should also be adjusted appropriately according to the personalized osteotomy line. Then bend the distractor's fixed piece in the software to further fit the bone surface.

H. According to the shape of the bent distractor, design a female mold of the distractor that closely fits its shape and save it in STL format. The structure of the female mold is shown in Figures 6 and 7.

I. According to the position of the three positioning parts of the affected mandible, the position of the nail hole and the position of the simulated osteotomy line, draw the outline of a guide plate on the outer bone surface of the affected mandible, and generate the guide plate in the embodiment with a thickness of 0.25mm The first positioning part, the second positioning part and the third positioning part, the inner surface of the guide plate is attached to the outer bone surface of the mandible.

J. Add positioning holes and guide separation lines to the guide plate according to the position of the distractor nail hole and the mandibular osteotomy line, as shown in Figures 2 and 3. At this time, the guide plate structure design is completed, and the designed guide plate is saved in STL format ；

K. Use three-dimensional printing materials to make the designed guide plate into a real object through the three-dimensional printing rapid prototyping method, as shown in Figures 4 and 5.

The guide plate in Example 1 can be made by the above method, which is specially designed for patients with underdeveloped unilateral mandible and secondary asymmetric deformities. The guide plate is assisted by computer software for simulation, which can avoid the design of the guide plate. The important anatomical structure improves the safety of the operation, can greatly save the cost of making models, save the time of operation design, and avoid errors caused by too many intermediate links. In the simulation process, based on the patient’s real patient situation, the designed guide plate can reduce the surgical error and improve the final surgical effect; and before the operation, the position of the distractor, the position of the nail hole and the direction of the osteotomy line are determined, and they are bent in advance The distractor is made, which saves operation time, improves operation efficiency, and reduces the burden on doctors and patients. The guide plate prepared by the method of this plan takes into account the overall consideration of the plan design for the operations that originally required two operations, which can avoid unnecessary treatments during the two operations to a certain extent, and may reduce some of the operations during the second-stage operation. It reduces the physical and economic burden of patients.

The specific application of the guide plate made by this scheme in surgery is as follows:

(1) Before the operation, take the female model as a reference, and bend the distractor used in the operation in advance to make it fit closely with the female model;

(2) Sterilize the digital guide plate and distractor for unilateral mandibular distraction osteogenesis;

(3) Under general anesthesia, an incision is made to the affected side of the submandibular external orifice, and the incision is made to the bone surface in layers. The muscle and soft tissue of the bone surface are peeled off. The guide plate is placed in the design area of the mandible outside, and three retention structures of the front, lower and back are made. At the same time, place the guide plate tightly on the bone surface of the mandible, drill holes according to the position of the guide plate and fix the guide plate with titanium nails;

(4) Use a reciprocating saw to cut the mandible according to the guide separation line on the guide plate, and check whether the mandible is completely disconnected;

(5) Remove the guide plate, place the distractor in the pre-designed position, as shown in Figure 8, and fix the distractor with titanium nails corresponding to the positioning holes drilled in step (3).

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. The protection scope, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A digital guide plate for mandibular distraction osteogenesis, which is characterized in that it comprises:

The upper source placed at the front end extends forward along the lateral surface of the patient's mandible and crosses the outer oblique line of the mandibular ascending branch to form the first positioning portion of the wrapping structure;

The sub-source placed at the front end extends downwards along the lateral surface of the patient's mandible and after approaching the mandibular foramen, it extends from the inner side of the mandible to form a second positioning part of the enveloping structure;

The third positioning part is placed at the rear end and extends along the outer and rear edge of the ascending mandibular branch to form a surrounding structure;

Used to guide bone drilling and titanium nails to fix the positioning holes of the distractor;

Guide separation line used to guide the direction of mandibular osteotomy.
The digital guide plate for mandibular distraction osteogenesis according to claim 1, wherein the thickness of the first positioning portion, the second positioning portion, and the third positioning portion is 2 to 3 mm.
The digital guide plate for mandibular distraction osteogenesis according to claim 1, wherein the thickness of the first positioning part, the second positioning part, and the third positioning part is 2.5 mm.
The digital guide plate for mandibular distraction osteogenesis according to claim 1, wherein the positioning holes are placed on the first positioning portion, the second positioning portion, and the third positioning portion, and each There are at least 3 positioning holes on the positioning part.
A method for manufacturing a digital guide plate for mandibular distraction osteogenesis, which is characterized in that it comprises the following steps:

A. Obtain the physical model of the patient's upper and lower dentition;

B. Determine the relative position of the upper and lower dentition physical model after the operation and mark it as the terminal occlusal relationship, and obtain the digital model Y of the patient's upper and lower dentition;

C. Establish a digital model A of the patient's cranio-maxillofacial bone tissue, and mark the position of the inferior alveolar nerve tube;

D. Match the digital model Y to the upper and lower dentition positions of the digital model A, and obtain the upper jaw and skull model B with accurate upper jaw dentition and the mandibular model C with accurate lower jaw dentition;

E. Simulate the osteotomy line of the mandible that needs to distract the osteogenesis side in the mandibular model C, and register the bone block containing the uninvolved mandible and mandibular dentition to the maxillary and skull model B according to the terminal occlusal relationship. Below, the mandibular model C and the upper jaw and skull model B are taken as a whole, with the contralateral condyle as the axis, according to the position of the bone block after the operation, to simulate the digital model D of the craniomaxillofacial surface after the operation;

F. In the cranio-maxillofacial digital model D, simulate the direction of the guide rod of the mandibular distraction osteogenesis distractor on the operating side;

G. Import the distractor model used in the operation and place the retractor according to the direction of the guide rod, and adjust the position of the distractor by translation to make it fit the mandible bone surface of the mandible model C to be distracted.

H. According to the shape of the bent distractor, the female mold of the distractor that closely fits the shape is designed;

I. According to the position of the three positioning parts of the ipsilateral mandible, the position of the nail hole and the position of the simulated osteotomy line, draw the contour of a guide plate on the outer bone surface of the ipsilateral mandible, and generate the guide plate of any one of claims 1 to 3 The first positioning part, the second positioning part and the third positioning part of, the inner surface of the guide plate fits with the outer bone surface of the mandible;

J. Add positioning holes and guide the separation line on the guide plate according to the position of the distractor nail hole and the mandibular osteotomy line;

K. Print the designed guide plate.